SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d70f058eb11f002e003e64d10007a178a9ee3fe6a9a61f5ffc72950fee09ba2' 
  AND token = '2EwTfIaaqcASxo98rdP07roMqLPbwlZaAqD7OIESStQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}